For times and prices try www.aquadelcenter.es Click 'English' under Logo top left, then pool time table under that. You will get prices there but not, of course, membership numbers.
Two of our guests intending to swim then eat there early last month were put off by a rather brusque and impatient manner in reception, the need to purchase bathing caps and the pool being marked off into lanes thus precluding casual swimming. They came back to the house - and had a pizza. Wonder if membership numbers reflect that approach to potential customers ?